Effects of taraxasterol on iNOS and COX-2 expression in LPS-induced RAW 264.7 macrophages

New cembranoid with potent anti-inflammatory effect isolated from Boswellia sacra by inactivating the NF-κB signaling pathway

Boswellia sacra has the properties of activating blood circulation, fixing pain, subduing swelling and promoting muscle growth. However, the anti-inflammatory active ingredients and molecular mechanisms of Boswellia sacra are still not clearly explored. Boswellia sacra was grounded and extracted using 95% ethanol, the extracts were separated by column chromatography preparation to give compounds. Spectral analysis and quantum calculations confirmed the structures of compounds and identified compound 1 as a new compound. Compounds 1-3 showed potent inhibitory activities and their effects on inflammatory mediator NO and inflammatory cytokines were examined by ELISA assay. Furthermore, their modulatory mechanism on inflammatory signal pathways was explored.

Potential Role of Dietary Phenolic Compounds in the Prevention and Treatment of Rheumatoid Arthritis: Current Reports

Rheumatoid arthritis (RA) is a complex illness with both hereditary and environmental components. Globally, in 2019, 18 million people had RA. RA is characterized by persistent inflammation of the synovial membrane that lines the joints, cartilage loss, and bone erosion. Phenolic molecules are the most prevalent secondary metabolites in plants, with a diverse spectrum of biological actions that benefit functional meals and nutraceuticals. These compounds have received a lot of attention recently because they have antioxidant, anti-inflammatory, immunomodulatory, and anti-rheumatoid activity by modulating tumor necrosis factor, mitogen-activated protein kinase, nuclear factor kappa-light-chain-enhancer of activated B cells, and c-Jun N-terminal kinases, as well as other preventative properties. This article discusses dietary polyphenols, their pharmacological properties, and innovative delivery technologies for the treatment of RA, with a focus on their possible biological activities. Nonetheless, commercialization of polyphenols may be achievable only after confirming their safety profile and completing successful clinical trials.

Orally fast dissolving α-lipoic acid electrospun nanofibers mitigates lipopolysaccharide induced inflammation in RAW 264.7 macrophages

α-Lipoic acid (LA), a dietary supplement known for its strong antioxidant and anti-inflammatory potential, faces challenges due to its poor aqueous solubility and thermal instability. To address these issues, herein methyl-beta-cyclodextrin (M-β-CD) was utilized to create inclusion complex (IC) of LA in 1:1 M stoichiometric ratio of M-β-CD to LA. The LA-M-β-CD-IC was further combined with pullulan (PUL), a non-toxic and water-soluble biopolymer, for the development of electrospun nanofibers (NF) by green and sustainable approach. The resulting PUL/LA/M-β-CD NF formed as a self-standing and flexible material with an average diameter of 569 ± 129 nm and encapsulation efficiency of ∼86.90 %. The developed NF demonstrated an accelerated release, quick dissolution, and disintegration when exposed to artificial saliva replicating the conditions of oral cavity. PUL/LA/M-β-CD NF attenuated the production of ROS and NO by downregulating pro-inflammatory enzymes (iNOS and COX-2) in lipopolysaccharide (LPS) stimulated RAW 264.7 cells. Moreover, PUL/LA/M-β-CD NF also significantly downregulated the expression of pro-inflammatory cytokines including TNF-α, IL-6, and IL-1β along with suppression of NF-ĸB nuclear translocation in comparison to LA (at 250 μM). In nutshell, PUL/LA/M-β-CD NF demonstrated great potential as a rapid disintegrating delivery system for oral anti-inflammatory treatment due to the enhanced physicochemical characteristics of LA.

Cynaroside improved depressive-like behavior in CUMS mice by suppressing microglial inflammation and ferroptosis

Depression is a common mental health disorder, and in recent years, the incidence of various forms of depression has been on the rise. Most medications for depression are highly dependency-inducing and can lead to relapse upon discontinuation. Therefore, novel treatment modalities and therapeutic targets are urgently required. Traditional Chinese medicine (TCM) offers advantages in the treatment of depression owing to its multi-target, multi-dimensional approach that addresses the root cause of depression by regulating organ functions and balancing Yin and Yang, with minimal side effects. Cynaroside (CNS), an extract from the traditional Chinese herb honeysuckle, is a flavonoid compound with antioxidant properties. In this study, network pharmacology identified 44 potential targets of CNS associated with depression and several highly correlated inflammatory signaling pathways. CNS alleviated LPS-induced M1 polarization and the release of inflammatory factors in BV-2 cells. Transcriptomic analysis and validation revealed that CNS reduced inflammatory polarization, lipid peroxidation, and ferroptosis via the IRF1/SLC7A11/GPX4 signaling pathway. In vivo experiments showed that CNS treatment had effects similar to those of fluoxetine (FLX). It effectively ameliorated anxiety-, despair-, and anhedonia-like states in chronic unpredictable mild stress (CUMS)-induced mice and reduced microglial activation in the hippocampus. Thus, we conclude that CNS exerts its therapeutic effect on depression by inhibiting microglial cells from polarizing into the M1 phenotype and reducing inflammation and ferroptosis levels. This study provides further evidence that CNS is a potential antidepressant, offering new avenues for the treatment of depression.

Identification of bioactive compounds and inhibitory effects of TNF-α and COX-2 in the extract from cultured three-spot seahorse (H. trimaculatus)

Three-spot seahorse (Hippocampus trimaculatus) has been consumed as traditional Chinese medicine in Asian society. This study was designed to analyze the bioactive compounds of the solvent extracts from cultured three-spot seahorse by high pressure liquid chromatography coupled with electrospray ionization tandem mass spectrometry (HPLC-ESI/MS/MS). Subsequently, their biological activities were evaluated and confirmed by cell modes and Western blot analysis. Experimental results indicated that taurine and arginine were the primary bioactive compounds identified and quantified without pre- or post-column derivatization within 20 min retention time. The analytical method was established and validated with intraday/interday RSD from 0.25% to 3.34% and with recovery from 87.8% to 91.2%. As compared to other extracts, water layer extract (WLE) contained the most taurine and arginine contents of 6.807 and 0.437 mg/g (dry basis), respectively. In the meanwhile, WLE also showed anti-inflammatory activity on LPS-induced NO production and inhibited the protein expression of TNF-α and COX-2 by Western blot analysis with better cell viability.

Effects of Encapsulation of Caesalpinia sappan L. with Cyclodextrins for Bovine Mastitis

The main components of Caesalpinia sappan L. (CS) are brazilin and brazilein, which show high potential in pharmacologic applications. However, these have been drastically limited by the poor water solubility and stability. The present study investigates the formation of inclusion complexes F1, F2, and F3 between CS and β-cyclodextrin (βCD), hydroxypropyl-β-cyclodextrin (HPβCD), and methyl-β-cyclodextrin (MβCD), respectively. These complexes were characterized by Fourier transform infrared spectroscopy (FT-IR). The results showed that the highest encapsulation efficiency and loading capacity of CS extract were 44.24% and 9.67%, respectively. The solubility and stability of CS extract were significantly increased through complexation in phase solubility and stability studies. The complexes F1-F3 showed mainly significant antibacterial activities on gram-positive bacteria pathogens causing mastitis. Moreover, the expression levels of COX-2 and iNOS were significantly decreased in LPS-induced inflammatory cells at concentrations of 50 and 100 µg/mL. In addition, treatment of complex F3 (CS/MβCD) in bovine endothelial cells remarkably increased the chemokine gene expression of CXCL3 and CXCL8, which were responsible for immune cell recruitment (9.92 to 11.17 and 8.23 to 9.51-fold relative to that of the LPS-treated group, respectively). This study provides a complete characterization of inclusion complexes between CS extract and βCD, HPβCD, and MβCD for the first time, highlighting the impact of complex formation on the pharmacologic activities of bovine mastitis.

Unsaturated Fatty Acids Complex Regulates Inflammatory Cytokine Production through the Hyaluronic Acid Pathway

In this study, we aimed to develop natural and/or functional materials with antioxidant and anti-inflammatory effects. We obtained extracts from natural plants through an oil and hot-water extraction process and prepared an extract composite of an effective unsaturated fatty acid complex (EUFOC). Furthermore, the antioxidant effect of the extract complex was evaluated, and the anti-inflammatory effect was explored by assessing its inhibitory effect on nitric oxide production through its HA-promoting effect. We conducted a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay to evaluate the cell viability of the EUFOC, and the results showed that EUFOC was not cytotoxic at the test concentrations. In addition, it showed no endogenous cytotoxicity in HaCaT (human keratinocyte) cells. The EUFOC showed excellent 1,1-diphenyl-2-picrylhydrazyl- and superoxide-scavenging abilities. Moreover, it exerted an inhibitory effect on NO production at concentrations that did not inhibit cell viability. The secretion of all the cytokines was increased by lipopolysaccharide (LPS) treatment; however, this was inhibited by the EUFOC in a concentration-dependent manner. In addition, hyaluronic acid content was markedly increased by the EUFOC in a dose-dependent manner. These results suggest that the EUFOC has excellent anti-inflammatory and antioxidant properties, and hence, it can be used as a functional material in various fields.

Taraxasterol alleviates aflatoxin B1-induced liver damage in broiler chickens via regulation of oxidative stress, apoptosis and autophagy

Aflatoxin B₁ (AFB₁) is the most dangerous and abundant mycotoxin, which is toxic to almost all animals, and poultry is more sensitive to AFB₁ toxicity. Ingesting AFB₁-contaminated feed can cause significant liver damage and brings serious harm to poultry, which greatly restricts the development of the poultry industry. The present research was implemented to explore the intervention effect and its mechanism of taraxasterol on liver damage induced by AFB₁ in broiler chickens. The liver damage model in broiler chickens was established by feeding 0.5 mg/kg AFB₁ feed, and taraxasterol (25, 50 and 100 mg/kg BW, respectively) was given in the drinking water for 21 days. The growth performance, liver function, oxidative stress, apoptosis and autophagy were evaluated. The results showed that taraxasterol increased BW and reduced feed-to-gain ratio of broiler chickens induced by AFB₁. Taraxasterol improved the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), total bilirubin (TBIL) and alkaline phosphatase (ALP), and attenuated hepatic histopathological changes induced by AFB₁. Meantime, taraxasterol down-regulated cytochrome P450 (CYP450) enzyme system CYP1A1 and CYP2A6 mRNA expression, inhibited the overproduction of reactive oxygen species (ROS) and malondialdehyde (MDA), and enhanced the activities of antioxidant enzymes glutathione (GSH) and catalase (CAT) and the content of antioxidant superoxide dismutase (SOD) of the liver in broiler chickens induced by AFB₁. Furthermore, taraxasterol up-regulated the mRNA and protein expression of hepatic nuclear factor E2 related factor 2 (Nrf2), heme oxygenase 1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1), and down-regulated the expression of hepatic kelch like ECH associated protein 1 (Keap1) induced by AFB₁ in Keap1/Nrf2 signaling pathway. The ultrastructural observation and RT-qPCR results found that taraxasterol inhibited apoptosis of hepatocytes, up-regulated the expression of B-cell lymphoma-2 (Bcl-2) mRNA and down-regulated the expression of Bax and caspase3 mRNA. Further, taraxasterol restored the autophagy of hepatocytes and down-regulated the mRNA expression of phosphatidylinositol 3-kinase K (PI3K), protein kinase B (AKT) and mammalian target of rapamycin (mTOR) in AFB₁-induced liver of broiler chickens. The above results indicate that taraxasterol alleviates liver damage induced by AFB₁ in broiler chickens through regulation of Keap1/Nrf2 signaling pathway to exert its antioxidant effect, mitochondrial apoptosis pathway to improve anti-apoptotic ability and PI3K/AKT/mTOR pathway to restore autophagy.

Echinacoside exerts antidepressant-like effects through enhancing BDNF-CREB pathway and inhibiting neuroinflammation via regulating microglia M1/M2 polarization and JAK1/STAT3 pathway

The present study was performed to investigate the antidepressant effect of echinacoside (ECH) using chronic unpredictable mild stress (CUMS) induced depression mice and lipopolysaccharide (LPS)-stimulated N9 microglial cells. CUMS treatment was performed on C57BL/6 mice for 28 days, followed by gavaging with different doses of echinacoside (15 and 60 mg/kg) for 21 consecutive days. Sucrose preference test (SPT), open field test (OFT), tail suspension test (TST), and forced swimming test (FST) were measured to assess the effects of echinacoside on CUMS-Induced Depressive-Like Behaviors. After that, the pathological changes of hippocampus were determined by Hematoxylin and eosin (HE) staining and Nissl staining; the neurotransmitters, pro-inflammatory cytokines and indoleamine 2,3-dioxygenase (IDO) levels, and the hypothalamic-pituitary-adrenal (HPA) axis activity were determined by enzyme linked immunosorbent assay (ELISA); Iba 1were evaluated by Immunofluorescence assay; Key protein expression levels of CREB/BDNF signal pathway were measured by western blotting. Subsequently, N9 cells were stimulated with 1 μg/ml LPS to induce N9 microglia activation, and were treated with 5-20 μM of echinacoside for 24 h. After that, the levels of NO, interleukin (IL)-1β, IL-6, tumor necrosis factor alpha (TNF-α), IL-4, IL-10, and transforming growth factor beta (TGF-β) in N9 cell culture supernatants were measured by enzyme-linked immunosorbent assay (ELISA) kits; morphology and Iba 1 expression level were observed by high-content screening assay; the M1 markers of CD11b, CD86 and M2 markers of CD206 were analyzed by imaging flow cytometry. Results show that treatment with echinacoside reversed CUMS-increased immobility time in OFT, TST, FST and reversed CUMS-reduced sucrose preference in SPT. In addition, echinacoside reduced the levels of pro-inflammatory cytokines and Iba 1. Moreover, echinacoside significantly increased p-CREB/CREB ratio and BDNF level in hippocampus. Furthermore, echinacoside reduced the secretion of inflammatory factors and inhibited microglia M1 polarization in N9 cells. In conclusion, echinacoside may be beneficial for the treatment of depression diseases through regulating the microglia balance by inhibiting the polarization of microglia to M1 phenotype, and improving hippocampal neurogenesis by the CREB-BDNF signaling pathway.

Protective Effect of the Polysaccharides from Taraxacum mongolicum Leaf by Modulating the p53 Signaling Pathway in H22 Tumor-Bearing Mice

Dandelion is an edible plant with a variety of bioactive components. This paper mainly reports the antitumor activity of dandelion polysaccharide DLP120 on H22 tumor-bearing mice. DLP120 is an acidic polysaccharide composed of pectin and arabinogalactan. The results indicate that DLP120 markedly inhibited tumor growth in a dose-dependent manner and attenuated and regulated negative effects on organs. In addition, DLP120 not only increased the viability of spleen lymphocytes and natural killer (NK) cells, but also increased the proportion of lymphocyte subsets in peripheral blood. Furthermore, Hematoxylin-Eosin (HE) staining showed that tumor tissues and cells exhibited typical pathology features. Annexin V FITC/PI staining and cell cycle distribution results further confirmed apoptosis and cell cycle arrest in S and G2 phases. Notably, there was a significant accumulation of reactive oxygen species. Western blotting results demonstrated that the expression of p53 was up-regulated in the DLP120 group. Moreover, the pro-apoptotic protein Bax was up-regulated while the inhibitory-apoptotic protein Bcl-2 was down-regulated. In addition, the expression of Fas and FasL, associated with the death receptor pathway, were also up-regulated. Overall, administration of DLP120 in H22 tumor-bearing mice can not only enhance immunity but also directly induce tumor cell apoptosis.

Taraxasterol Inhibits Hyperactivation of Macrophages to Alleviate the Sepsis-induced Inflammatory Response of ARDS Rats

To explore the effect and mechanism of taraxasterol on sepsis-induced acute respiratory distress syndrome (ARDS). Twenty-four male SD rats were randomly divided into four groups: the control group, model (lipopolysaccharide, LPS) group, lipopolysaccharide+taraxasterol (LPS + TXL) group, and lipopolysaccharide+ulinastatin (LPS + UTI) group. The model of sepsis-induced ARDS was established by intraperitoneal injection of LPS. The lung water content of the rats in each group was determined by the dry/wet ratio. Pathology of rat lung tissue was observed through H&E staining. Wright staining was applied to count the number of neutrophils, macrophages, and total cells. ELISA was utilized to measure the levels of the inflammatory factors TNF-α, IL-1β, and IL-6 in bronchoalveolar lavage fluid (BALF). Biochemical detection was adopted to check the levels of myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) in lung tissue. Western blotting was performed to check the protein expression of IL-12, iNOS, Arg-1, and Mrc1 in lung tissue. Compared with the LPS group, both taraxasterol and ulinastatin significantly decreased lung tissue water content, improved lung tissue injury, reduced the number of neutrophils, macrophages and total cells, and decreased the level of inflammatory factors. In addition, taraxasterol and ulinastatin also reduced the content of MPO and the expression of IL-12 and iNOS and increased the activity of SOD and CAT as well as the protein expression of Arg-1 and Mrc1. Taraxasterol can suppress macrophage M1 polarization to alleviate the inflammatory response and oxidative stress, thereby treating sepsis-induced ARDS.

The potential of dandelion in the fight against gastrointestinal diseases: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Dandelion (Taraxacum officinale Weber ex F. H. Wigg.), as a garden weed grown globally, has long been consumed as a therapeutic herb. Its folkloric uses include treatments of digestive disorders (dyspepsia, anorexia, stomach disorders, gastritis and enteritis) and associate complex ailments involving uterine, liver and lung disorders.

AIM OF THE STUDY

The present study aims to critically assess the current state of research and summarize the potential roles of dandelion and its constituents in gastrointestinal (GI) -protective actions. A focus is placed on the reported bioactive components, pharmacological activities and modes of action (including molecular mechanisms and interactions among bioactive substances) of dandelion products/preparations and derived active constituents related to GI protection.

MATERIALS AND METHODS

The available information published prior to August 2021 was reviewed via SciFinder, Web of Science, Google Scholar, PubMed, Elsevier, Wiley On-line Library, and The Plant List. The search was based on the ethnomedical remedies, pharmacological activities, bioactive compounds of dandelion for GI protection, as well as the interactions of the components in dandelion with the gut microbiota or biological regulators, and with other ingested bioactive compounds. The key search words were "Taraxacum" and "dandelion".

RESULTS

T. coreanum Nakai, T. mongolicum and T. officinale are the most commonly used species for folkloric uses, with the whole plant, leaves and root of dandelion being used more frequently. GI-protective substances of dandelion include taraxasterol, taraxerol, caffeic acid, chicoric acid, chlorogenic acid, luteolin and its glucosides, polysaccharides, inulin, and β-sitosterol. Dandelion products and derived constituents exhibit pharmacological effects against GI disorders, mainly including dyspepsia, gastroesophageal reflux disease, gastritis, small intestinal ulcer, ulcerative colitis, liver diseases, gallstones, acute pancreatitis, and GI malignancy. The underlying molecular mechanisms may include immuno-inflammatory mechanisms, apoptosis mechanism, autophagy mechanism, and cholinergic mechanism, although interactions of dandelion's constituents with GI health-related biological entities (e.g., GI microbiota and associated biological modulators) or other ingested bioactive compounds shouldn't be ignored.

CONCLUSION

The review reveals some in vivo and in vitro studies on the potential of dandelion derived products as complementary and alternative medicines/therapeutics against GI disorders. The whole herb may alleviate some symptoms related GI immuno-inflammatory basing on the abundant anti-inflammatory and anti-oxide active substances. Dandelion root could be a nontoxic and effective anticancer alternative, owing to its abundant terpenoids and polysaccharides. However, research related to GI protective dandelion-derived products remains limited. Besides the need of identifying bioactive compounds/complexes in various dandelion species, more clinical studies are also required on the metabolism, bioavailability and safety of these substances to support their applications in food, medicine and pharmaceuticals.

Anti-Inflammatory and Antiproliferative Properties of Sweet Cherry Phenolic-Rich Extracts

Cherries have largely been investigated due to their high content in phenolics in order to fully explore their health-promoting properties. Therefore, this work aimed to assess, for the first time, the anti-inflammatory potential of phenolic-targeted fractions of the Saco cherry, using RAW 264.7 macrophages stimulated with lipopolysaccharide. Additionally, the cytotoxic effects on gastric adenocarcinoma (AGS), neuroblastoma (SH-SY5Y) and normal human dermal fibroblast (NHDF) cells were evaluated, as well as the ability to protect these cellular models against induced oxidative stress. The obtained data revealed that cherry fractions can interfere with cellular nitric oxide (NO) levels by capturing NO radicals and decreasing inducible nitric oxide synthase and cyclooxygenase-2 expression. Furthermore, it was observed that all cherry fractions exhibited dose-dependent cytotoxicity against AGS cells, presenting cytotoxic selectivity for these cancer cells when compared to SH-SY5Y and NHDF cells. Regarding their capacity to protect cancer cells against oxidative injury, in most assays, the total cherry extract was the most effective. Overall, this study reinforces the idea that sweet cherries can be incorporated into new pharmaceutical products, smart foods and nutraceuticals.

Peony seed oil ameliorates neuroinflammation-mediated cognitive deficits by suppressing microglial activation through inhibition of NF-κB pathway in presenilin 1/2 conditional double knockout mice

Chronic neuroinflammation has been shown to exert adverse influences on the pathology of Alzheimer's disease (AD), associated with the release of abundant proinflammatory mediators by excessively activated microglia, causing synaptic dysfunction, neuronal degeneration, and memory deficits. Thus, the prevention of microglial activation-associated neuroinflammation is important target for deterring neurodegenerative disorders. Peony seed oil (PSO) is a new food resource, rich in α-linolenic acid, the precursor of long chain omega-3 polyunsaturated fatty acids, including docosahexaenoic acid and eicosapentaenoic acid, which exhibit anti-inflammatory properties by altering cell membrane phospholipid fatty acid compositions, disrupting lipid rafts, and inhibiting the activation of the proinflammatory transcription factor NF-κB. However, few studies have examined the anti-neuroinflammatory effects of PSO in AD, and the relevant molecular mechanisms remain unclear. Presenilin1/2 conditional double knockout (PS cDKO) mice display obvious AD-like phenotypes, such as neuroinflammatory responses, synaptic dysfunction, and cognitive deficits. Here, we assessed the potential neuroprotective effects of PSO against neuroinflammation-mediated cognitive deficits in PS cDKO using behavioral tests and molecular biologic analyses. Our study demonstrated that PSO suppressed microglial activation and neuroinflammation through the down-regulation of proinflammatory mediators, such as inducible NOS, COX-2, IL-1β, and TNF-α, in the prefrontal cortex and hippocampus of PS cDKO mice. Further, PSO significantly lessened memory impairment by reversing hyperphosphorylated tau and synaptic proteins deficits in PS cDKO mice. Importantly, PSO's therapeutic effects on cognitive deficits were due to inhibiting neuroinflammatory responses mediated by NF-κB signaling pathway. Taken together, PSO may represent an effective dietary supplementation to restrain the neurodegenerative processes of AD.

Dandelion sterol improves diabetes mellitus-induced renal injury in in vitro and in vivo study

The purpose of our research was to evaluate Dandelion sterol's treatment effects on diabetes mellitus-induced renal injury in in vitro and in vivo study. The rats were divided into five groups as normal control (Ctrl), diabetic nephropathy model (Model), Dandelion sterol low-dose treated (Dan-Low), Dandelion sterol middle-dose treated (Dan-Middle), and Dandelion sterol high-dose treated (Dan-High). Measuring serum TNF-α, IL-1β, and IL-6 concentrations by Elisa assay, evaluate kidney pathology by HE staining, kidney cell apoptosis of TUNEL, TLR4, and NF-κB(p65) proteins expression by IHC assay, and relative gene expressions by RT-qPCR assay. In the following step, using HK-2 treated with high glucose to model DN cell model to discuss the relative mechanisms, evaluate TNF-α, IL-1β, and IL-6 concentrations by Elisa assay, evaluate cell apoptosis by flow cytometry, evaluate TLR4 and NF-κB(p65) proteins expression by WB assay, relative gene expression by RT-qPCR assay, and NF-κB(p65) nuclear volume by cellular immunofluorescence. Compared with Ctrl group, TNF-α, IL-1β, and IL-6 concentrations and apoptosis cell number were significantly increased, TLR4/NF-κB(p65) pathway was significantly stimulated in Model rats and cell groups. With Dan supplement, the diabetic-induced renal injury was significantly improved (p < .05, respectively). By cell experiment, Dan improved cell apoptosis and inflammatory factors via miR-140-5p. Dan improved diabetes mellitus-induced renal injury via regulation of miR-140-5p/TLR4 axis in in vitro and in vivo study.

Effects of Eye Drops Containing Hyaluronic Acid-Nimesulide Conjugates in a Benzalkonium Chloride-Induced Experimental Dry Eye Rabbit Model

Dry eye syndrome (DES) is a common ocular disease worldwide. Currently, anti-inflammatory agents and immunosuppressive drugs, such as cyclosporine A, have been widely used to treat this chronic condition. However, the multifactorial etiology of DES, poor tolerance, low bioavailability, and prolonged treatment to response time have limited their usage. In this study, nimesulide, a cyclooxygenase (COX)-2 selective inhibitor, was conjugated with hyaluronic acid (HA), and the HA-nimesulide conjugates were expected to increase the solubility and biocompatibility for alleviating the DES in the benzalkonium chloride (BAC)-induced goblet cell-loss dry eye model. The therapeutic efficacy of HA-nimesulide was assessed using fluorescein staining, goblet cell density by conjunctival impression cytology, and histology and immunohistochemistry of corneal tissues. Compared to commercial artificial tears and Restasis®, the HA-nimesulide conjugates could promote goblet cell recovery and enhance the regeneration of the corneal epithelium. Importantly, immunofluorescent staining studies demonstrated that the HA-nimesulide conjugates could decrease the number of infiltrating CD11b-positive cells after two weeks of topical application. In the anti-inflammatory test, the HA-nimesulide conjugates could inhibit the production of pro-inflammatory cytokines and prostaglandin E2 (PGE2) in the lipopolysaccharide (LPS)-stimulated Raw 264.7 cell model. In conclusion, we demonstrated that HA-nimesulide conjugates had anti-inflammatory activity, and promoted goblet cell recovery and corneal epithelium regeneration when used as topical eye drops; accordingly, the HA-nimesulide conjugates could potentially be effective for the treatment of DES.

Benzoylaconine Modulates LPS-Induced Responses Through Inhibition of Toll-Like Receptor-Mediated NF-κB and MAPK Signaling in RAW264.7 Cells

Previous studies have shown that benzoylaconine (BAC), a representative monoester alkaloid, has a potential anti-inflammatory effect. This study investigated the underlying molecular mechanisms using the mode of LPS-activated RAW264.7 macrophage cells. Our findings showed that BAC significantly suppressed the release of pro-inflammatory cytokines and mediators, including IL-6, TNF-α, IL-1β, ROS, NO, and PGE₂. BAC treatment also effectively downregulated the elevated protein levels of iNOS and COX-2 induced by LPS in a dose-dependent manner. In this study, we found that BAC inhibited LPS-induced NF-κB activation by reducing the phosphorylation and degradation of IκBα by western blotting and blocking the nuclear translocation of p65 using an immunofluorescence assay. The elevated protein levels of JNK, p38, and ERK phosphorylation after LPS stimulation were restored effectively by BAC treatment. The protein expression of Toll-like receptor 4 (TLR4) and LPS-induced phosphorylation of TAK1, which is a crucial upstream regulatory factor of TLR-induced MAPK and NF-κB signaling, were inhibited by BAC in activated RAW264.7 macrophages. Moreover, BAC decreased the levels of TAK1 phosphorylation and pro-inflammatory cytokines and mediators associated with MAPK and NF-κB activation, similar to TLR4 inhibitor TAK-242. These findings demonstrated that BAC exhibited an anti-inflammatory effect by the inhibition of TLR-induced MAPK and NF-κB pathways, indicating that it could potentially be used for treating inflammatory diseases.

Anti-Inflammatory Effect Fraction of Bletilla striata and Its Protective Effect on LPS-Induced Acute Lung Injury

Bletilla striata is a well-known traditional Chinese herb with anti-inflammatory properties that is widely used in the treatment of lung conditions such as silicosis, tuberculosis, and pneumogastric hemorrhage. However, little information on the anti-inflammatory ingredients and their activities is available. In this study, an effect fraction of Bletilla striata (EFBS) was enriched, and its anti-inflammatory activities and underlying mechanisms were investigated. EFBS was enriched by polyamide column chromatography and characterized by HPLC; an LPS-induced acute lung injury model was used to evaluate the anti-inflammatory activities of EFBS. Meanwhile, the main anti-inflammation-contributing ingredients and possible molecular mechanism of anti-inflammatory activity in EFBS were verified by component-knockout method combined with LPS-induced RAW264.7 cell model. The EFBS mainly consisted of coelonin (15.88%), batatasin III (32.49%), 3′-O-methylbatatasin III (6.96%), and 3-hydroxy-5-methoxy bibenzyl (2.51%). Pretreatment with the EFBS (20 mg/kg and 60 mg/kg) for five days prior to the administration of LPS resulted in decreases in wet-to-dry lung weight ratio, neutrophil number, MPO activity, total protein concentration, NO level, and MDA level, as well as IL-1β, IL-6, MCP-1, and TNF-α concentrations in the bronchoalveolar lavage fluid. Western blot analysis demonstrated the increased expressions of iNOS, COX-2, and NF-κB p65 in the LPS treatment group, all of which were ameliorated by EFBS pretreatment. Histological examination confirmed the protective effect of the EFBS. Additionally, component-knockout assay confirmed that these four quantitative components contributed significantly to the anti-inflammatory effect of EFBS. Coelonin, batatasin III, 3′-O-methylbatatasin III and 3-hydroxy-5-methoxy bibenzyl were the main anti-inflammatory components of EFBS and could regulate the expression of downstream inflammatory cytokines by inhibiting p65 nuclear translocation. These findings uncover, in part, the molecular basis underlying the anti-inflammatory activity of Bletilla striata.

Pinus thunbergii Parl. Extracts Reduce Acute Inflammation by Targeting Oxidative Stress

Pinus thunbergii Parl. (PTP) has traditionally been used for edible and medicinal purposes to treat several disorders, including diabetes and neuralgia. Therefore, this study sought to evaluate the inhibitory effects of PTP leaf ethanol extracts on acute inflammation. Moreover, the reactive oxygen species (ROS) scavenging activity, superoxide dismutase (SOD) activity, lipopolysaccharide (LPS)-induced nitric oxide (NO) generation, and H₂O₂-induced lipid peroxidation capacity of PTP were assessed in vitro in RAW 264.7 macrophages. Our results suggest that PTP prevents cell damage caused by oxidative free radicals and downregulates the expression of LPS-induced inflammation-associated factors including inducible nitric oxidase synthetase (iNOS), cyclooxygenase-2 (COX-2), and prostaglandin E₂ (PGE₂). PTP inhibited NO production by 53.5% (P < 0.05) and iNOS expression by 71.5% (P < 0.01) at 100 µg/mL. PTP at 100 µg/mL also inhibited ROS generation by 58.2% (P < 0.01) and SOD activity by 29.3%, as well as COX-2 expression by 83.3% (P < 0.01) and PGE2 expression by 98.6% (P < 0.01). The anti-inflammatory effects of PTP were confirmed in vivo using an arachidonic acid (AA)-induced ear edema mouse model. Ear thickness and myeloperoxidase (MPO) activity were evaluated as indicators of inflammation. PTP inhibited edema formation by 64.5% (P < 0.05) at 1.0 mg/ear. A total of 16 metabolites were identified in PTP extracts and categorized into subgroups, including two phenolic acids (mainly quinic acid), seven flavonoids, five lignans, one sesquiterpenoid, and one long-chain fatty acid. Therefore, our results suggest that PTP possesses anti-inflammatory properties.

Sodium Butyrate Alleviates Lipopolysaccharide-Induced Inflammatory Responses by Down-Regulation of NF-κB, NLRP3 Signaling Pathway, and Activating Histone Acetylation in Bovine Macrophages

Sodium butyrate is the sodium salt of butyric acid, which possesses many biological functions including immune system regulation, anti-oxidant and anti-inflammatory ability. The present study was designed to elucidate the anti-inflammatory effects and mechanisms of sodium butyrate on lipopolysaccharide (LPS)-stimulated bovine macrophages. The effect of sodium butyrate on the cell viability of bovine macrophages was assayed by using the CCK-8 kit. Quantitative real-time PCR (qRT-PCR) was used to detect the gene expression of interleukin-6 (IL-6), interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), and inducible Nitric Oxide Synthase (iNOS). NF-κB, NLRP3 signaling pathway, and histone deacetylase were detected by western blotting. The results showed that sodium butyrate had no significant effect on cell viability at 0-1 mM, and inhibited LPS-induced IL-6, IL-1β, COX-2, and iNOS expression. Moreover, sodium butyrate suppressed LPS (5 μg/ml)-stimulated the phosphorylation of IκB and p65, inhibited the deacetylation of histone H3K9, and has also been found to inhibit protein expression in NLRP3 inflammasomes. Thus, our finding suggested that sodium butyrate relieved LPS-induced inflammatory responses in bovine macrophage by inhibiting the canonical NF-κB, NLRP3 signaling pathway, and histone decetylation, which might be helpful to prevent cow mastitis.

Effects of taraxasterol against ethanol and high-fat diet-induced liver injury by regulating TLR4/MyD88/NF-κB and Nrf2/HO-1 signaling pathways

Studies have reported that taraxasterol (TAR) is effective in the treatment of immune liver injury and alcoholic liver injury. The mechanism of action is mainly related to the inhibition of inflammation. To determine the key molecular mechanisms for the effect of TAR on alleviating ethanol and high-fat diet-induced liver injury, pathological morphology, biochemistry, oxidative stress, inflammatory response and lipid metabolism were examined. Our results showed that TAR could inhibit ethanol-induced hepatocyte death or lipid accumulation, and suppress oxidative stress, inflammatory response and lipid metabolism disorders. More specifically, ethanol-induced TLR-4 and MyD88 inflammatory response were down-regulated, when treated with TAR. Production of CYP2E1, Nrf2 and HO-1, which produced in response to increased oxidative stress, were regulated in TAR treated, ethanol-induced hepatocytes. In summary, TAR could inhibit the inflammatory response and oxidative stress, which was related to the regulation of TAR on TLR-4/MyD88/NF-κB and Nrf2/HO-1 pathways.

Plant triterpenoid saponins: biosynthesis, in vitro production, and pharmacological relevance

The saponins are a diverse class of natural products, with a broad scale distribution across different plant species. Chemically characterized as triterpenoid glycosides, they posses a 30C oxidosqualene precursor-based aglycone moiety (sapogenin), to which glycosyl residues are subsequently attached to yield the corresponding saponin. Based on the chemically distinct aglycone moieties, broadly, they are divided into triterpenoid saponins (dammaranes, ursanes, oleananes, lupanes, hopanes, etc.) and the sterol glycosides. This review aims to present in detail the biosynthesis patterns of the different aglycones from a common precursor and their glycosylation patterns to yield the functionally active glycoside. The review also presents recent advances in the pharmacological activities of these saponins, particularly as potent anti-neoplastic pharmacophores, antioxidants, or anti-viral/antibacterial agents. Since alternate production pedestals for these pharmacologically important triterpenes via cell and tissue cultures are an attractive option for their sustainable production, recent trends in the variety and scale of in vitro production of plant triterpenoids have also been discussed.

Cloning and Characterization of Oxidosqualene Cyclases Involved in Taraxasterol, Taraxerol and Bauerenol Triterpene Biosynthesis in Taraxacum coreanum

Triterpenes, consisting of six isoprene units, are one of the largest classes of natural compounds in plants. The genus Taraxacum is in the family Asteraceae and is widely distributed in the Northern Hemisphere. Various triterpenes, especially taraxerol and taraxasterol, are present in Taraxacum plants. Triterpene biosynthesis occurs through the action of oxidosqualene cyclase (OSC), which generates various types of triterpenes from 2,3-oxidosqualene after the rearrangement of the triterpene skeleton. However, no functional characterization of the OSC genes involved in triterpene biosynthesis, except for a lupeol synthase in Taraxacum officinale, has been performed. Taraxacum coreanum, or Korean dandelion, grows in Korea and China. Putative OSC genes in T. coreanum plants were isolated by transcriptome analysis, and four of these (TcOSC1, TcOSC2, TcOSC3 and TcOSC4) were functionally characterized by heterologous expression in yeast. Both TcOSC1 and TcOSC2 were closely related to dammarenediol-II synthases. TcOSC3 and TcOSC4 were strongly grouped with β-amyrin synthases. Functional analysis revealed that TcOSC1 produced several triterpenes, including taraxasterol; Ψ-taraxasterol; α-, β- and δ-amyrin; and dammarenediol-II. TcOSC2 catalyzed the production of bauerenol and another unknown triterpene, TcOSC3 catalyzed the production of β-amyrin. TcOSC4 catalyzed the production of taraxerol. Moreover, we identified taraxasterol, ψ-taraxasterol, taraxerol, lupeol, δ-amyrin, α-amyrin, β-amyrin and bauerenol in the roots and leaves of T. coreanum. Our results suggest that TcOSC1, TcOSC2, TcOSC3 and TcOSC4 are key triterpene biosynthetic enzymes in T. coreanum. These enzymes are novel triterpene synthases involved in the production of taraxasterol, bauerenol and taraxerol.

Human disorders associated with inflammation and the evolving role of natural products to overcome

Inflammation is a biological function which triggered after the mechanical tissue disruption or from the responses by the incidence of physical, chemical or biological negotiator in body. These responses are essential act provided by the immune system during infection and tissue injury to maintain normal tissue homeostasis. Inflammation is a quite complicated process at molecular level with the involvement of several proinflammatory expressions. Several health problems are associated with prolonged inflammation, which effects nearly all major to minor diseases. The molecular and epidemiological studies jagged that the inflammation is closely associated with several disorders with their specific targets. It would be great achievement for human health around the world to overcome on inflammation. Mostly used anti-inflammatory drugs are at high risk of side effects and also expensive. Hence, the plant-based formulations gained a wide acceptance by the public and medical experts to treat it. Due to extensive dispersal, chemical diversity and systematically established biological potentials of natural products have induced renewed awareness as a gifted source for medications. However, today's urgent need to search for cheaper, more potent and safe anti-inflammatory medications to overcome on current situation. The goal of this review to compile an update on inflammation, associated diseases, molecular targets, inflammatory mediators and role of natural products. The entire text concise the involvement of various cytokines in pathogenesis of various human disorders. This assignment discussed about 321 natural products with their promising anti-inflammatory potential discovered during January 2009 to December 2018 with 262 citations.

Ameliorative potential of flavonoids of Aegle marmelos in vincristine-induced neuropathic pain and associated excitotoxicity

Introduction: The objective of the study is to elucidate the effect of Aegle marmelos bark hydroalcoholic extract (AMHE) and the role of its constituents marmelosin, umbelliferone, and Para-coumaric acid in attenuating neuropathic pain.Methodology: Peripheral neuropathy was induced by vincristine 100 μg/ml. AMHE was administered in three dose levels (100, 200 and 300 mg/kg) for 21 days. Mechanical hyperalgesia and allodynia were assessed by Randall Sellitto and electronic Von-Frey test, respectively. Functional loss and recovery of the nerve were assessed by sciatic functional index test. The nerve conduction velocity and formalin test were done to assess the peripheral and central response of the extract. Inflammatory mediators in both sciatic nerve and brain and neurotransmitters glutamate and aspartate were measured to support the data.Results and discussion: The inflammatory mediators in both sciatic nerve and brain (TNF-α, IL-1β, and IL-6) were found to be attenuated with AMHE-treated group in comparison to the group treated only with vincristine, which indicates the extract has anti-inflammatory property. AMHE treated rats were found to be active in all the behavioural tests, suggesting its activity could be mediated through a central and peripheral mechanism to attenuate the pain response. The levels of excitatory neurotransmitters were found to be reduced with AMHE treatment.Conclusion: It could be concluded that AMHE is active in attenuating the neuropathic pain caused by vincristine. The peripheral action would have mediated through lowering the inflammatory mediators as well as the excitotoxicity caused due to peripheral neuropathy and neuroinflammation.

Anti-Inflammatory Effects of Taraxasterol on LPS-Stimulated Human Umbilical Vein Endothelial Cells

In the present study, we used the human umbilical vein endothelial cells (HUVECs) to investigate the anti-inflammatory effects and mechanism of taraxasterol on vascular inflammation. HUVECs were pre-treated with taraxasterol 1 h before lipopolysaccharide (LPS) treatment. The concentrations of TNF-α, IL-8, PGE2, and NO were measured. The expression of VCAM-1, ICAM-1, iNOS, COX-2, NF-κB, and LXRα was detected by western blot analysis. The results showed that taraxasterol not only reduced the production of TNF-α, IL-8, PGE2, and NO induced by LPS, but also reduced the expression of iNOS and COX-2. Taraxasterol also suppressed LPS-induced NF-κB activation and VCAM-1 and ICAM-1 expression. Furthermore, taraxasterol concentration-dependently increased the expression of LXRα. The inhibition of taraxasterol on TNF-α, IL-8, PGE2, and NO production can be reversed by geranylgeranyl diphosphate (GGPP, the LXRα inhibitor). Here, we found that taraxasterol inhibited vascular inflammation through activating LXRα.

Esculentoside B inhibits inflammatory response through JNK and downstream NF-κB signaling pathway in LPS-triggered murine macrophage RAW 264.7 cells

Natural compound esculentoside B (EsB), (2S,4aR,6aR,6aS,6bR,8aR,9R,10R,11S,12aR,14bS)-11-hydroxy-9-(hydroxymethyl)-2 methoxycarbonyl-2,6a,6b,9,12a-pentamethyl-10-[(2S,3R,4S,5R)-3,4,5-trihydroxyoxan-2-yl]oxy-1,3,4,5,6,6a,7,8,8a,10,11,12,13,14b-tetradecahydropicene-4a-carboxylic acid with molecular weight of 664.833, isolated from roots of Phytolacca acinosa Roxb has been widely used as a constituent of traditional Chinese medicine (TCM). However, the anti-inflammatory capacity of EsB has not been reported yet. Therefore, the objective of this study was to investigate anti-inflammatory activities of EsB in LPS-treated macrophage RAW 264.7 cells. EsB could inhibit nitric oxide (NO) production. EsB also suppressed gene and protein expression levels of inducible isoform of NO synthase (NOS) and cyclooxygenase-2 in a dose-dependent manner. In addition, EsB decreased gene expression and protein secretion levels of pro-inflammatory cytokines such as IL-1β, TNF-α, and IL-6. EsB remarkably suppressed nuclear translocation of nuclear factor kappa-B (NF-κB) from cytosolic space. Phosphorylation of IκB was also inhibited by EsB. Moreover, EsB specifically down-regulated phospho-c-Jun N-terminal kinase (p-JNK), but not p-p38 or phospho-extracellular signal-regulated kinase 1/2 (p-ERK1/2). Taken together, these results suggest that EsB has inhibitory effect on inflammatory response by inactivating NF-κB and p-JNK. It could be used as a new modulatory drug for effective treatment of inflammation-related diseases.

In Vitro and In Vivo Protective Effects of Flavonoid-Enriched Lotus Seedpod Extract on Lipopolysaccharide-Induced Hepatic Inflammation

Endotoxin lipopolysaccharide (LPS) plays an important role in the acceleration of hepatic inflammation. Natural medicinal plants that can prevent inflammation by targeting LPS have potential therapeutic clinical application. The aim of the study is to examine the anti-inflammatory effects of lotus seedpod extract (LSE), used as a traditional Chinese herbal medicine with hemostasis function and for eliminating bruise, on the LPS-induced hepatic inflammation and its underlying molecular mechanisms in vitro and in vivo. In vitro, LSE and its purified compound (-)-epigallocatechin (EGC) dose-dependently inhibited the expressions of pro-inflammatory cytokines and mediators, including tumor necrosis factor (TNF)- α , interleukin (IL)-6, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), without affecting cell viability in LPS-stimulated human hepatoma cell line HepG2. Molecular studies showed the anti-LPS effect of HLP or EGC might be mediated via downregulation of Toll-like receptor 4. (TLR4)-mediated both NF- κ B and p38 signaling, as demonstrated by the usage of pyrrolidine dithiocarbamate (PDTC), a specific NF- κ B inhibitor. In vivo, LPS-induced hepatic inflammation was significantly ameliorated in LSE-fed mice as gauged by dose-dependent inhibition of serum levels of biochemical markers of liver damage, the changes of hepatic lobular architecture and the secretion of pro-inflammatory mediators, as well as induction of anti-oxidant enzymes. As a result, our data presented the first evidence of EGC-enriched LSE as an anti-inflammatory agent in LPS-stimulated HepG2 cells and mice, and these findings may open interesting perspectives to the strategy in treatment for hepatic inflammation.

Protective Effects of Taraxasterol against Ethanol-Induced Liver Injury by Regulating CYP2E1/Nrf2/HO-1 and NF-κB Signaling Pathways in Mice

Taraxasterol, a pentacyclic-triterpene compound, is one of the main active components isolated from the traditional Chinese medicinal herb Taraxacum. The objective of this study is to evaluate the protective effects of taraxasterol and its possible underlying mechanisms against ethanol-induced liver injury in mice. ICR mice were fed with Lieber-DeCarli diet containing 5% ethanol for 10 d and then challenged with a single dose of 20% ethanol (5 g/kg BW) by intragastric administration. The mice were intragastrically treated daily with taraxasterol (2.5, 5, and 10 mg/kg). Tiopronin was used as a positive control. The liver index was calculated, and the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in sera were detected. The contents of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH) and the activity of superoxide dismutase (SOD) in the livers were measured. The histopathological changes of liver tissues were observed by hematoxylin and eosin (H&E) staining. The protein expression levels of hepatic cytochrome P450 2E1 (CYP2E1), nuclear factor erythroid 2-related factor 2 (Nrf2), antioxidant protein heme oxygenase-1 (HO-1), and nuclear factor-kappa B (NF-κB) signaling pathway in liver tissues were detected by immunohistochemistry and Western blot methods. Taraxasterol significantly reduced the ethanol-induced increases of liver index, ALT, AST, and TG levels in sera and TG and MDA contents in the livers and hepatic ROS production and suppressed the ethanol-induced decreases of hepatic GSH level and SOD activity. Taraxasterol also significantly inhibited the secretion of proinflammatory cytokines TNF-α and IL-6 induced by ethanol. In addition, taraxasterol improved the liver histopathological changes in mice with ethanol-induced liver injury. Further studies revealed that taraxasterol significantly inhibited the ethanol-induced upregulation of CYP2E1, increased the ethanol-induced downregulation of Nrf2 and HO-1, and inhibited the degradation of inhibitory kappa Bα (IκBα) and the expression level of NF-κB p65 in liver tissues of ethanol-induced mice. These findings suggest that taraxasterol possesses the potential protective effects against ethanol-induced liver injury in mice by exerting antioxidative stress and anti-inflammatory response via CYP2E1/Nrf2/HO-1 and NF-κB signaling pathways.

Taraxasterol Inhibits LPS-Induced Inflammatory Response in BV2 Microglia Cells by Activating LXRα

Neuroinflammation plays a critical role in the development of neurodegenerative diseases. Taraxasterol, a pentacyclic-triterpene isolated from Taraxacum officinale, has been reported to have anti-inflammatory effect. The aim of this study was to investigate the anti-inflammatory effects and mechanism of taraxasterol in LPS-stimulated BV2 microglia cells. BV2 microglia cells were treated with taraxasterol 12 h before LPS stimulation. The effects of taraxasterol on LPS-induced TNF-α and IL-1β production were detected by ELISA. The effects of taraxasterol on LXRα, ABCA1, TLR4, and NF-κB expression were detected by western blot analysis. The results showed that taraxasterol dose-dependently inhibited LPS-induced TNF-α and IL-1β production and NF-κB activation. Taraxasterol also disrupted the formation of lipid rafts and inhibited translocation of TLR4 into lipid rafts. Furthermore, taraxasterol was found to activate LXRα-ABCA1 signaling pathway which induces cholesterol efflux from cells. In addition, our results showed that the anti-inflammatory effect of taraxasterol was attenuated by transfection with LXRα siRNA. In conclusion, these results suggested that taraxasterol inhibits LPS-induced inflammatory response in BV2 microglia cells by activating LXRα-ABCA1 signaling pathway.

Genipin inhibits allergic responses in ovalbumin-induced asthmatic mice

Genipin is a natural compound isolated from the fruit of Gardenia jasminoides with various pharmacological effects. In this study, we investigated whether genipin effectively alleviates allergic responses in a murine model of ovalbumin (OVA)-induced asthma. The mice were administered an intraperitoneal injection of OVA on day 0 and 14 to boost the immune response; genipin was then administered from day 18 to 23 by oral gavage. On days 21 to 23, mice were OVA-challenged using am ultrasonic nebulizer, and airway hyperresponsiveness (AHR) was determined on day 24 by plethysmography. Genipin significantly reduced the inflammatory cell count in bronchoalveolar lavage fluids (BALF) and AHR, which were accompanied by lower interleukin-5 (IL-5), IL-13 and OVA-specific immunoglobulin (Ig) E levels in the BALF or serum from OVA-induced asthmatic mice. In histology, genipin significantly decreased airway inflammation and mucus hypersecretion in OVA-induced asthmatic mice. Additionally, genipin inhibited OVA-induced increases in the expression of inducible nitric oxide synthase and cyclooxygenase-2 proteins. Further, genipin reduced the activity and protein levels of matrix metalloproteinase-9 in lung tissue from OVA induced asthmatic mice. Overall, genipin effectively alleviated the asthmatic inflammatory response in an OVA-induced asthmatic model. Therefore, our results suggest that genipin has therapeutic potential for treating asthma.

Immune-Stimulatory Effects of Althaea rosea Flower Extracts through the MAPK Signaling Pathway in RAW264.7 Cells

Althaea rosea (Linn.) is a medicinal plant from China and Korea that has been traditionally used to control inflammation, to stop bedwetting and as a mouthwash in cases of bleeding gums. Its flowers are employed medicinally for their emollient, demulcent and diuretic properties, which make them useful in chest complaints. Furthermore, a flower extract decoction is used to improve blood circulation, for the treatment of constipation, dysmenorrhoea, haemorrhages, etc. However, the possible mechanisms of the immune-stimulatory effect remains to be elucidated. Therefore, we investigated the role of Althaea rosea flower (ARF) extracts in the immune-stimulatory effect of macrophages and the underlying mechanisms of action. ARF water extract (ARFW) could dose-dependently increase NO production and cytokines (IL-6 and TNF-α). We also found that ARFW significantly increased the expression of iNOS and COX-2 proteins in RAW264.7 cells. Consistent with these results, MAPK protein (JNK, ERK, p38) expression levels were induced after treatment with ARFW. Additionally, ARFW showed a marked increase in the phosphorylation level of IκBα and subsequent IκBα degradation allowing NF-κB nuclear translocation. These results suggest that the immune-stimulatory effect of A. rosea flower extracts is mediated through the translocation of NF-κB p65 subunit into the nucleus from the cytoplasm and subsequent activation of pro-inflammatory cytokines (IL-6 and TNF-α) and other mediators (iNOS and COX-2), which occurs mainly through MAPK signalling pathway. Thus, we suggest that ARFW could be considered as a potential therapeutic agent useful in the development of immune-stimulatory compounds.

Protective effect of taraxasterol against rheumatoid arthritis by the modulation of inflammatory responses in mice

Taraxasterol is an effective component of dandelion that has anti-inflammatory effects in vivo and in vitro. The present study was performed to explore whether taraxasterol exhibits a protective effect against rheumatoid arthritis through the modulation of inflammatory responses in mice. Eight-week-old CCR9-deficient mice were injected with a collagen II monoclonal antibody cocktail to create a rheumatoid arthritis model. In the experimental group, arthritic model mice were treated with 10 mg/kg taraxasterol once per day for 5 days. Treatment with taraxasterol significantly increased the pain thresholds and reduced the clinical arthritic scores of the mice in the experimental group compared with those of the model group. Furthermore, treatment with taraxasterol significantly suppressed tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and nuclear factor-κB protein expression levels compared with those in the rheumatoid arthritis model mice. Taraxasterol treatment also significantly reduced nitric oxide, prostaglandin E2 and cyclooxygenase-2 levels compared with those in the rheumatoid arthritis model group. These observations indicate that the protective effect of taraxasterol against rheumatoid arthritis is mediated via the modulation of inflammatory responses in mice.

Taraxasterol inhibits cigarette smoke-induced lung inflammation by inhibiting reactive oxygen species-induced TLR4 trafficking to lipid rafts

Taraxasterol, a pentacyclic-triterpene isolated from Taraxacum officinale, has been demonstrated to have anti-inflammatory effects. However, the protective effects of taraxasterol against cigarette smoke (CS)-induced lung inflammation have not been reported. This study aimed to investigate the protective effects and mechanism of taraxasterol on CS-induced lung inflammation in mice. CS-induced mouse lung inflammation model was used to investigate the protective effects of taraxasterol in vivo. Human bronchial epithelial cells (HBECs) were used to investigate the protective mechanism of taraxasterol in vitro. The results showed that taraxasterol attenuated CS-induced lung pathological changes, inflammatory cells infiltration, inflammatory cytokines TNF-α, IL-6 and IL-1β production. Taraxasterol also up-regulated CS-induced glutathione (GSH) production. In vitro, taraxasterol was found to inhibit CS-induced reactive oxygen species production, recruitment of TLR4 into lipid rafts, NF-κB activation, and IL-8 production. Furthermore, our results showed that antioxidant N-acetyl-L-cysteine (NAC) significantly inhibited CS-induced recruitment of TLR4 into lipid rafts as well as IL-8 production. In conclusion, our results suggested that taraxasterol had protective effects of CS-induced lung inflammation.

Anti-inflammatory and anti-arthritic effects of taraxasterol on adjuvant-induced arthritis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Taraxasterol was isolated from the traditional Chinese medicinal herb Taraxacum which has been frequently used as a remedy for inflammatory diseases. In the present study, we determined the in vivo anti-arthritic effect of taraxasterol on arthritis induced by Freund's complete adjuvant (FCA) in rats.

MATERIALS AND METHODS

Rats were immunized with FCA by intradermal injection into the right hind metatarsal footpad, and were orally treated daily with taraxasterol at 2, 4 and 8mg/kg from day 2-28 after immunization. Paw swelling, arthritis index, body weight, spleen index and thymus index were evaluated. The levels of TNF-α, IL-1β, PGE2, OPG and RANKL in sera were measured using ELISA. Histopathological changes in joint tissues were examined using hematoxylin and eosin (H&E).

RESULTS

Taraxasterol significantly suppressed paw swelling and arthritis index, attenuated body weight loss, decreased the spleen index and thymus index induced by FCA. Furthermore, taraxasterol significantly inhibited the overproduction of serum TNF-α, IL-1β, PGE2 and RANKL, and increased serum OPG production in FCA-induced rats. Histopathological examination indicated that taraxasterol attenuated synovial hyperplasia, bone and cartilage damage, and inflammatory cell infiltration.

CONCLUSIONS

These results suggest that taraxasterol has the potential protective effect against FCA-induced arthritis in rats.

Bioactive Extract from Moringa oleifera Inhibits the Pro-inflammatory Mediators in Lipopolysaccharide Stimulated Macrophages

Introduction:

Inflammation is a well-known physiological response to protect the body against infection and restore tissue injury. Nevertheless, the chronic inflammation can trigger various inflammatory associated diseases/disorder. Moringa oleifera is a widely grown plant in most tropical countries and it has been recognized traditionally for several medicinal benefits.

Objectives:

The objective of this study was to investigate the anti-inflammatory properties of M. oleifera extract on lipopolysaccharide (LPS) - stimulated macrophages.

Materials and Methods:

The anti-inflammatory effect of M. oleifera hydroethanolic bioactive leaves extracts was evaluated by assessing the inhibition of nitric oxide (NO) production during Griess reaction and the expression of pro-inflammatory mediators in macrophages.

Results:

Interestingly, we found that M. oleifera hydroethanolic bioactive leaves extract significantly inhibited the secretion of NO production and other inflammatory markers such as prostaglandin E₂, tumor necrosis factor alpha, interleukin (IL)-6, and IL-1β. Meanwhile, the bioactive extract has induced the production of IL-10 in a dose-dependent manner. In addition, M. oleifera hydroethanolic bioactive leaves extract effectively suppressed the protein expression of inflammatory markers inducible NO synthase, cyclooxygenase-2, and nuclear factor kappa-light-chain-enhancer of activated B-cells p65 in LPS-induced RAW264.7 macrophages in a dose-dependent manner.

Conclusion:

These findings support the traditional use of M. oleifera plant as an effective treatment for inflammation associated diseases/disorders.

SUMMARY

Hydroethanolic extracts of Moringa oleifera effectively inhibit the NO production in LPS induced inflammatory model.

M. oleifera crude extracts successfully modulate the production of pro-inflammatory mediators in LPS stimulated macrophages.

M. oleifera extracts suppressed the expression of inflammatory mediators in LPS stimulated macrophages.

Inhibitory Effects of Polydatin on Lipopolysaccharide-Stimulated RAW 264.7 Cells

The purpose of this study was to evaluate the effects of polydatin (PD) on cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expressions at protein and transcriptional levels, as well as the production of prostaglandin E2 (PGE2) and nitric oxide (NO) in lipopolysaccharide (LPS)-induced macrophage RAW 264.7 cells. To elucidate the underlying mechanism responsible for these symptoms, we investigated the phosphorylation of mitogen-activated protein kinase (MAPK) pathway and nuclear factor-κB (NF-κB) expression. NO was analyzed with the Griess method. PGE2 was measured by enzyme-linked immunosorbent assay (ELISA). iNOS and COX-2 messenger RNA (mRNA) were identified by qPCR assay. iNOS, COX-2, NF-κB, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 protein expressions were detected with Western blot. The results revealed that PD effectively inhibited NO and PGE2 production, and it is not surprising that PD reduced iNOS and COX-2 expression at protein and transcriptional levels. Additionally, PD significantly ameliorated the activation of NF-κB and the phosphorylation of MAPKs in LPS-induced RAW 264.7 macrophages. These findings suggested that PD exerted potent anti-inflammatory activity in macrophages.

Mulberry fruit prevents LPS-induced NF-κB/pERK/MAPK signals in macrophages and suppresses acute colitis and colorectal tumorigenesis in mice

Here, we investigated the impact of mulberry fruit (MBF) extracts on lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 macrophages, and the therapeutic efficacy of MBF diet in mice with dextran sulfate sodium (DSS)-induced acute colitis and MUC2^−/− mice with colorectal cancer. In vitro, LPS-induced nitric oxide (NO) production was significantly inhibited by MBF extracts via suppressing the expression of proinflammatory molecules, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-1 beta (IL-β) and IL-6. Particularly, a dose-dependent inhibition on LPS-induced inflammatory responses was observed following treatment with MBF dichloromethane extract (MBF-DE), in which linoleic acid and ethyl linolenate were identified as two active compounds. Moreover, we elucidated that MBF-DE attenuated LPS-induced inflammatory responses by blocking activation of both NF-κB/p65 and pERK/MAPK pathways. In vivo, DSS-induced acute colitis was significantly ameliorated in MBF-fed mice as gauged by weight loss, colon morphology and histological damage. In addition, MBF-fed MUC2^−/− mice displayed significant decrease in intestinal tumor and inflammation incidence compared to control diet-fed group. Overall, our results demonstrated that MBF suppressed the development of intestinal inflammation and tumorgenesis both in vitro and in vivo, and supports the potential of MBF as a therapeutic functional food for testing in human clinical trials.

Taraxacum officinale and related species-An ethnopharmacological review and its potential as a commercial medicinal plant

ETHNOPHARMACOLOGICAL RELEVANCE

Dandelion (Taraxacum spec) is a wild plant that has been used for centuries as a traditional medicine in the relief and treatment of several diseases. This use is due to the presence of sesquiterpenes, saponins, phenolic compounds, flavonoids, and sugars, among others, found in the organs of the plant.

AIM OF THE STUDY

The aim of this work is to provide a current review of developments and trends in research on the Taraxacum genus, with a focus on traditional uses and pharmacological properties. This should shed light on the potential of this plant as an attractive commercial herbal medicine.

MATERIALS AND METHODS

Documents were collected, analyzed, and classified for information regarding medical, agronomic, genetic, and biological aspects of the Taraxacum species. This process was based on a thorough search of documents indexed by scientific search engines.

RESULTS

Two important periods of research on Taraxacum have been identified: the first, between 1930 and 1950; and the second, from 1990 to today. During the former, agricultural and genetics research on this plant were, due to the shortage of natural rubber, the focus. In contrast, the main drive in Taraxacum research is now the recovery of bioactives and/or applications in medicine. Pharmacology is the main area in which these plants have been tested, thanks in part to its widely known traditional uses; however, there is less than enthusiastic interest in further human clinical trials. In other areas, Taraxacum sports an enormous list of compounds of industrial interest; and while it is true that only a small amount of these compounds is immediately available in Taraxacum organs and makes it relatively commercially unattractive, only scarce efforts have been made to improve yields. Compounding this issue, most studies of its growth and cultivation have been focused mainly on controlling it as a weed detrimental to certain industrial crops. To wit, in spite of all the research carried out, less than 1% of all the species identified so far (>2500) have been studied (including Taraxacum officinale, Taraxacum coreanum, Taraxacum mongolicum and Taraxacum platycarpum). This is a indication of the little knowledge that we have about this genus so far. Biotechnology (involving genetics, agriculture, and biology) is the most powerful means by which to take advantage of all the medicinal potential of Taraxacum. Great strides have been made in identifying metabolic pathways for synthesizing terpenes, one of the most important compound families in clinical applications. In order to improve yield and performance of the plant in the field, greenhouse cultivation is another aspect taken into account, deriving an increase in recovery of bioactives from Taraxacum organs. Even while considering that only a few species have been studied, their different biochemical and cultivation profiles indicate huge potential for qualitative improvements in composition through genetic engineering, thus directly impacting pharmacological properties.

CONCLUSIONS

Taraxacum is has been traditionally considered a natural remedy, well-inserted into popular knowledge, but with low commercial applicability. Only once the recovery of pure and highly reactive compounds can be pursued at (a qualitatively and quantitatively attractive) economical scale, human clinical trials would be of interest in order to prove their efficacy and safety, positioning Taraxacum as an important commercial source of natural drugs.

Quantification of taraxasterol in rat plasma by LC/MS/MS: application to a pharmacokinetic study

Taraxasterol, a pentacyclic triterpene from Taraxacum officinale, is one of the main active constituents of the herb. This study developed and validated a highly selective and sensitive liquid chromatography/tandem mass spectrometry for the determination of taraxasterol in rat plasma over the range of 9.0-5000 ng/mL. Chromatographic separation was achieved on a C18 (4.6 × 50 mm, 5.0 µm) column with methanol-isopropanol-water-formic acid (80:10:10:0.1, v/v/v/v) as mobile phase with an isocratic elution. The flow rate was 0.7 mL/min. After adding cucurbitacin IIa as an internal standard (IS), liquid-liquid extraction was used for sample preparation using ethyl acetate. The atmospheric pressure chemical ionization source was applied and operated in positive ion mode. Selected reaction monitoring mode was used for the quantification of transition ions m/z 409.4 → 137.1 for taraxasterol and m/z 503.4 → 113.1 for IS. The mean recoveries of taraxasterol in rat plasma ranged from 85.3 to 87.2%. The matrix effects for taraxasterol were between 98.5 and 104.0%. Intra- and inter-day precision were both <11.8%, and the accuracy of the method ranged from -7.0 to 12.9%. The method was successfully applied to a pharmacokinetic study of taraxasterol after oral administration of 7.75, 15.5 and 31.0 mg/kg in rats.

Taraxasterol inhibits IL-1β-induced inflammatory response in human osteoarthritic chondrocytes

Osteoarthritis (OA), a chronic degenerative joint disease, is a leading cause of disability among elderly patients. Taraxasterol, a pentacyclic-triterpene isolated from Taraxacum officinale, has been shown to have anti-inflammatory effects. However, the protective effect of taraxasterol on OA remains unclear. In order to provide a scientific basis for the applicability of taraxasterol in OA, the anti-inflammatory effects of taraxasterol on IL-1β-stimulated osteoarthritic chondrocytes were investigated. Chondrocytes were pretreated with taraxasterol 1h before IL-1β treatment. The productions of MMP-1, MMP3, MMP13, PGE2 and NO were measured by ELISA and Griess reaction. The expression of COX-2, iNOS, and NF-κB was detected by western blot analysis. Our results demonstrated that taraxasterol dose-dependently suppressed MMP-1, MMP3, MMP13, PGE2 and NO production induced by IL-1β. The expression of COX-2 and iNOS was also inhibited by taraxasterol. Western blot analysis showed that taraxasterol suppressed IL-1β-induced NF-κB activation in a dose-dependent manner. Taken together, we found that taraxasterol protected human chondrocytes by inhibiting MMPs, NO and PGE2 production. Taraxasterol may be a useful agent for prevention and treatment of OA.